* {
    margin: 0;
    padding: 0;
}

.top {
    height: 50px;
    background-color: aqua;
    display: flex;
    justify-content: space-around;
    align-items: center;
}

.top > div:last-child {
    cursor: pointer;
    background-color: rebeccapurple;
    height: 50px;
    line-height: 50px;
    padding: 0 20px;
}

.top + div {
    display: flex;
}

.left {
    width: 200px;
    height: calc(100vh - 50px);
    background-color: aliceblue;
    /*display: flex;*/
    /*justify-content: center;*/
    text-align: center;
}

.left > div > div {
    width: 200px;
}

.left > div > div:hover {
    background-color: aquamarine;
}

.left > div > div > div:nth-child(2) {
    text-indent: 2em;
    display: none;
}

.left > div > div > div:nth-child(1) {
    /*font-size: 30px;*/
    line-height: 50px;
    font-weight: bold;
}

.left > div > div > div:nth-child(2) > div:hover {
    background-color: rebeccapurple;
}

/*.left > div > div:first-child {*/
/*    background-color: aquamarine;*/
/*}*/

/*.left > div > div:first-child > div:nth-child(2) {*/
/*    display: block;*/
/*}*/


.right {
    width: calc(100vw - 200px);
    height: calc(100vh - 50px);
    overflow: auto;
}
